An electric power meter having a communication function to measure an amount of electric power consumption digitally and notify a power company of the measured amount of electric power consumption by using a communication line (a so-called smart meter) is about to be introduced.
The smart meter notifies a concentrator of the measured amount of electric power consumption. The concentrator is notified of amounts of electric power consumption by several hundred smart meters. The concentrator notifies the power company of the amount of electric power consumption measured by each smart meter.
The concentrator notifies a server of the amount of electric power consumption of each household by, for example, a wireless communication of a cellular scheme. In some cases, the concentrator is provided on the back surface of the smart meter. Since the smart meter has metal components such as a transformer, degradation in antenna performance is expected.